ABQG BGP Community NMTIE 10/17/2008

Transcription

1 ABQG BGP Community NMTIE 1

2 Albuquerque Gigapop Network Aggregation Point in Central New Mexico Keeping New Mexico network traffic in New Mexico 2

3 Tilte: ABQG BGP Community standard Summary: ABQG (Albuquerque Gigapop), the New Mexico on-ramp service provider to Internet 2 and National Lambda Rail (NLR), also provides Local peering service for New Mexico local entities. The session will focus on BGP (Border Gateway Protocol) community strings that ABQG uses to serve its own peering partners and how peering partners can take advantage of this attribute for route manipulation. Co-Presenter: Ed May - Network Engineer UNM/ABQG emay@unm.edu Paul Chang - Network Engineer UNM/ABQG pchang@unm.edu 3

4 Session Pre-requisites Interested in peering with ABQG Somewhat familiar with BGP (Border Gateway Routing Protocol) 4

5 5

6 Prefixes in ABQG routing table BGP peer NLR I2 R&E I2 CPS TWTC UNM Checs LANL Esnet CABQG Total Prefix learned ,004 6

7 119,000 + Too many prefixes!!!! How to scale this to be manageable? 7

8 Typical given requests: Newly peered client A wants to get UNM routes; I2 R&E routes but no LANL Routes ; no I2 CPS routes. 8

9 Using BGP attributes: AS origin AS Path, Next HOP, MED, Local preference. BGP Community is the Answer! 9

10 ABQG BGP Community assignment ABQG AS: Connector AS ==== 40498:XX Items Community Value Description Status Service type :4323 TWTC Commodity Service :19401 NLR 10G NLR Service :19402 NLR 1G NLR Service :11537 I2 R&E I2 Service :11538 I2 CPS I2 Service :3388 UNM primary Peering partner :3389 UNM secondary Peering partner :68 LANL Peering partner :3912 Checsnet Peering partner :293 Esnet Peering partner :26439 CABQ Peering partner :17153 NMT Coming soon Peering partner :64516 NMCAC NMCAC dedicated Note 1. By defaults peering partner prefixes are announced to all ABQG peering partners 2. Community string listed above are additive. 10

11 How does it work? From ABQG side ABQG tags all incoming prefixes learned with ABQG BGP community standard additively. ABQG then announce prefix to its clients based on what type of combination services client selects. Now the control plant is set up for this particular clients. When packet hit ABQG router, data plant will route traffic based on the control plant info 11

12 How is it done? From ABQG side BGP Mantra: Incoming policy affects outgoing traffic Outgoing policy affects incoming traffic. Example of the set up. 12

13 How to configure it? A. Leg work first some global configuration ip as-path access-list 1 permit ^$ ip as-path access-list 68 permit ^3388_ ip bgp-community new-format ip community-list 11 permit 40498:4323 ip community-list 12 permit 40498:19401 ip community-list 13 permit 40498:19402 ip community-list 14 permit 40498:11537 ip community-list 15 permit 40498:11538 ip community-list 16 permit 40498:3388 ip community-list 17 permit 40498:3389 ip community-list 18 permit 40498:68 ip community-list 19 permit 40498:3912 ip community-list 21 permit 40498:293 ip community-list 22 permit 40498:26439 ip community-list 23 permit 40498:17153 B. Route-map set up secondly so it can later applied to BGP peer: route-map ITSin permit 10 match as-path 68 set local-preference 100 set community 40498:3388 addictive! route-map ITSin permit 20 route-map ITSout permit 10 match as-path 1! route-map ITSout permit 20 match community C. Finally apply to routing policy for this peer: router bgp address-family ipv4 neighbor send-community both neighbor route-map ITSin in neighbor route-map ITSout out D. Check the bgp routes to see whether community is properly applied. E. Check whether the routes announced to your BGP peer is based on the community string list you applied. 13

14 Inspecting prefix sent by AS DREN 14

15 How does it work? From ABQG client side. (Name few possibilities) Do nothing Filter prefix(es) based on community value Filter prefix(es) based on combination of community value and AS origin Etc.. 15

16 Case Study I Redundancy backup commodity service breaks between two ABQG partners. Solution: Use ABQG community string attribute to manipulate inbound route policy to fix it. (See details ) 16

17 What do we achieve here? 1. Make routing policy task scalable 2. Provide easy maintenance and set up for peering arrangement What are other alternatives and limitations? Using MP-BGP VRFs MPLS-VPN 17

18 ABQG Stats 18

19 References: 1. ABQG web site : 2. UNM Enterprise Command Center (ECC) : 3. ABQG BGP community : 4. NLR community : 5. I2 Community : 6. Verizon Business Community and practice: List/BGP-Community-String-for-Verizon-Business-AS701.html 7. BGP best path selection: 8. This presentation: 19

20 Q&A 20